Thin and flexible electronic displays are of great interest for application in wearable devices, electronic newspapers, smart identity cards and many other consumer electronics. Such flexible electronic displays have been realized in active matrix organic light emitting diode (AMOLED) displays. Specifically, in the AMOLED displays, thin film transistor (TFT) devices are made on flexible substrates by depositing thin films of an active semiconductor layer in conjunction with dielectric insulation layers and metallic contacts. The flexible substrates are temporarily attached to rigid carriers that provide sufficient mechanical support to the flexible substrates during the course of preparing the TFT devices and the corresponding AMOLED displays. After the TFT devices and the corresponding AMOLED displays are formed on the flexible substrates, the flexible substrates have to be detached from the rigid carriers without causing damages to the TFT devices or display elements of the AMOLED displays formed thereon.
An excimer laser has often been applied to release a flexible substrate from a rigid carrier. The excimer laser has been used to treat an interface between the flexible substrate and the rigid carrier when the flexible substrate is formed directly on the rigid carrier, and to treat a sacrificial layer when the flexible substrate is coupled to the rigid carrier via the sacrificial layer. However, the use of the excimer laser is normally associated with a high tool cost, and does not have a high production yield to provide a satisfactory throughput of the flexible substrate.
Alternatively, some prior art manufacturing methods manage to reduce adhesion force between the flexible substrate and the rigid carrier when the flexible substrate is formed on the rigid carrier directly (e.g., use an adhesion control layer between the flexible substrate and the rigid carrier). Due to reduction of the adhesion force, mechanical force can be applied to peel the flexible substrate from the underlying rigid carrier, which therefore involves a significantly less tool cost than the use of the excimer laser. However, there has always been a challenge to control the adhesion force between the flexible substrate and the rigid carrier properly so as to ease the mechanical detachment while still maintaining sufficiently strong attachment of the flexible substrate to the rigid carrier for the purposes of supporting the display manufacturing process.
Therefore, it would be beneficial to have a flexible substrate that can be easily detached from a rigid carrier while not compromising the robustness of the flexible substrate and the quality of display devices formed thereon during a display manufacturing process.